Upper Brittany

Upper Brittany was a Norse kingdom in Brittany which existed from 847 to 891 and then from 914 to 939. In 847, the Vikings launched a brutal attack on Brittany which resulted in its occupation, and the Vikings came to rule a portion of the peninsula, with Hasteinn ruling as their king. The Vikings occasionally allied with the Bretons, jointly attacking Le Mans in 865. From 888 to 891, the Bretons managed to reclaim Upper Brittany from the Vikings, but, in 914, Rold and Ottir conquered Brittany and forced the nobility to flee to England and Francia. The Vikings under Rognvald conquered the whole country, establishing Nantes as their capital. Despite the region's wealth and strategic location, no efforts were ever made to settle it, and much of the country became derelict. In 931, the Vikings invaded Francia from Nantes, and they had to crush a failed Breton rebellion caused by their absence. In 936, Alan Barbetorte launched an invasion of Brittany from England, and Nantes was retaken after a fierce battle in 937 and the Vikings were expelled from their fort at Trans in 939, ending their rule in Brittany.